Embodiments herein generally relate to systems that bill for printing documents and more particularly to a method that bases the multi-color/single-color billing distinction on the colorspace of the documents being printed and ignores any multi-color indications received from the print drivers.
In certain instances, customers of printing services are incorrectly billed for color printing charges when they choose black and white or grayscale printing. For example, in some existing multi-function devices, if a user scans a document to file or to e-mail, and if the user specifically chooses grayscale as the desired portable document format (PDF) option, the file is captured in PDF with the colorspace calibrated gray (CalGray). This allows for device independence, allowing (in theory) any printer to get and render the same output. Similarly, choosing “Black” from the standard Adobe print driver interface can cause the color space attribute CalGray (Adobe print drivers are available from Adobe Systems Incorporated, San Jose, Calif., USA).
However, in spite of the fact that CalGray is intended to represent image data exclusively as 256 gray levels, with no chromatic data, and no accompanying ICC profile, many printers recognize CalGray documents as color. This would lead to, among other things, customers being charged for color prints, even for strictly monochrome images. The interpretation of CalGray documents as color can be seen by using Adobe Acrobat Pro 7.0 preflight tools, which generates the message “Document generates more than one plate”, where plate refers to an offset press plate, one for each process color. While one specific print driver is mentioned above, the embodiments discussed below, which address these issues, apply to all similar printer intermediaries and print drivers.